The ongoing rapid miniaturisation of optoelectronics has led to an increased interest in generation, characterisation and interconnection of optoelectronic elements with characteristic dimensions in the sub-micrometer or nanometer length scale regime. The requirements of the optically active element(s) in a sub-micro- or nanoscale optoelectronic component include such features as an easy optical tunability, a strong luminescence efficiency, flexibility in the molecular basis elements and that light should be generated or propagate in a predefined way. Organic optically active elements may fulfil such requirements.
A difficulty is that normally it is impossible, inconvenient or economically unfeasible to form the organic sub-micro- or nanoscale optically active elements and components directly on a desired substrate.
A solution to this is to form the optically active element on a different substrate—a formation substrate or template—and subsequently transfer the element to the desired substrate. Known techniques for releasing and transferring sub-micro- or nanoscale elements include ablation, adhesive lift-off techniques, removing the formation substrate from the backside by milling, such as ion milling, chemical dissolution of the formation substrate. However, these methods may require multiple steps and may produce excessive waste materials or may simply not work, e.g. because the optically active elements are not transferred in an unaltered way.
WO 01/92150 describes a method for transferring carbon nanotubes to a substrate. The method can be understood from FIGS. 2 through 6 as follows:                FIGS. 2+3: A lump of carbon nanotubes 1a is dissolved in a solvent 4 by the application of a supersonic wave 5, to create a carbon nanotube-solution 6. The supersonic wave has:                    frequency [20-200 kHz]            amplitude [0.5-50 μm]            for a time of [0.1-10 hours]                        FIG. 4: The carbon nanotube-solution 6 is filtered through filer 7 whereby a carbon nanotube thin film 1 is created on filter 7.        FIGS. 5+6: A binder layer 3 is formed on the thin film 1, and the structure is turned upside-down on a substrate 2. The filter 7 can now be torn off and the binder layer 3 can be dissolved by heat treatment, resulting in the formation of a carbon nanotube thin film 1 on substrate 2.        
Hence WO 01/92150 relates to the transfer of a lump of carbon nanotubes to a substrate.
The inventors of the present invention have appreciated that an improved method of releasing sub-micro- or nanoscale elements from a substrate, and thereby facilitating transferring of sub-micro- and nanoscale elements is of benefit, and has in consequence devised the present invention.